554
Process model A conceptual or mathematical representation of a process that
attempts to represent component steps or mechanisms (c.f. empirical or statistical model).
Producer’s accuracy The fraction of correctly classified pixels in the reference
dataset used to train a model. Contrast to user’s accuracy.
Propagule Plant material that can become detached and develop into a new organism (e.g., seeds, spores, corms, tubers, stems or rhizomes, etc.).
Provisioning ecosystem services The material or energy outputs from ecosystems that benefit—and are generally consumed by—humans, including fuel,
fiber, food, clean water, and other resources. Also called Nature’s Contributions
to People (NCPs) within the IPBES framework.
Proximal remote sensing Observations from a close distance, usually in the
range of centimeters to meters. Also known as close-range remote sensing or
near-surface remote sensing. Typically uses trams, platforms, tractors, and UASs
for deployment or is even handheld.
Proximal sensors Sensors mounted on platforms on or near the ground that collect information in close proximity to the target of interest.
Quadrat Square frame used to define a small study area for ecological studies.
Radar Acronym for radio detection and ranging. It involves methods, systems,
techniques, and equipment for using the timing of transmitted, reflected, and
detected electromagnetic radiation to detect, locate, and track objects or to measure abiotic and biotic surface and subsurface traits. In remote sensing, usually
encompasses imaging synthetic aperture radar (SAR) wavelengths 3–70 cm (frequencies 435 MHz to 8 GHz).
Radiance Radiant flux density emanating from a surface per unit solid angle.
Units are often given in watts per steradian per square meter, W·sr
−1
·m
−2
. Spectral
radiance units would also include wavelength (e.g., nm
−1
).
Radiative transfer The transfer and propagation of electromagnetic energy
through a medium (e.g., the atmosphere, a forest canopy, the water column),
involving absorption, scattering, and emission of radiation as described by the
fundamental radiative transfer equation. These processes are modeled to describe
the relationship between the characteristics of the medium and reflectance.
Radiative transfer modeling in remote sensing, radiative transfer modeling
(RTM) pertains to the use of computer programs of varying complexity to simulate the reflectance, transmittance, and absorption of solar radiation within different media such as the atmosphere (air, clouds, aerosols), snow, water, and
vegetation (leaves and canopies). In each of these domains, physical laws govern
the scattering and absorbing behavior of the radiation. RTMs are used to predict
the shape of the spectral response from the characteristics of a specific material
(forward mode), or to predict material characteristics from spectra (backward
mode). Specific RTMs are developed using a wide range of assumptions, different model representations, and a range of approaches to simplify the solution
to the full radiative transfer equation, resulting in a range of model complexities with trade-offs between computational demand, accuracy, and scalability.
All RTMs require inputs in the form of external conditions (e.g., incident solar
Glossary
Process model A conceptual or mathematical representation of a process that
attempts to represent component steps or mechanisms (c.f. empirical or statistical model).
Producer’s accuracy The fraction of correctly classified pixels in the reference
dataset used to train a model. Contrast to user’s accuracy.
Propagule Plant material that can become detached and develop into a new organism (e.g., seeds, spores, corms, tubers, stems or rhizomes, etc.).
Provisioning ecosystem services The material or energy outputs from ecosystems that benefit—and are generally consumed by—humans, including fuel,
fiber, food, clean water, and other resources. Also called Nature’s Contributions
to People (NCPs) within the IPBES framework.
Proximal remote sensing Observations from a close distance, usually in the
range of centimeters to meters. Also known as close-range remote sensing or
near-surface remote sensing. Typically uses trams, platforms, tractors, and UASs
for deployment or is even handheld.
Proximal sensors Sensors mounted on platforms on or near the ground that collect information in close proximity to the target of interest.
Quadrat Square frame used to define a small study area for ecological studies.
Radar Acronym for radio detection and ranging. It involves methods, systems,
techniques, and equipment for using the timing of transmitted, reflected, and
detected electromagnetic radiation to detect, locate, and track objects or to measure abiotic and biotic surface and subsurface traits. In remote sensing, usually
encompasses imaging synthetic aperture radar (SAR) wavelengths 3–70 cm (frequencies 435 MHz to 8 GHz).
Radiance Radiant flux density emanating from a surface per unit solid angle.
Units are often given in watts per steradian per square meter, W·sr
−1
·m
−2
. Spectral
radiance units would also include wavelength (e.g., nm
−1
).
Radiative transfer The transfer and propagation of electromagnetic energy
through a medium (e.g., the atmosphere, a forest canopy, the water column),
involving absorption, scattering, and emission of radiation as described by the
fundamental radiative transfer equation. These processes are modeled to describe
the relationship between the characteristics of the medium and reflectance.
Radiative transfer modeling in remote sensing, radiative transfer modeling
(RTM) pertains to the use of computer programs of varying complexity to simulate the reflectance, transmittance, and absorption of solar radiation within different media such as the atmosphere (air, clouds, aerosols), snow, water, and
vegetation (leaves and canopies). In each of these domains, physical laws govern
the scattering and absorbing behavior of the radiation. RTMs are used to predict
the shape of the spectral response from the characteristics of a specific material
(forward mode), or to predict material characteristics from spectra (backward
mode). Specific RTMs are developed using a wide range of assumptions, different model representations, and a range of approaches to simplify the solution
to the full radiative transfer equation, resulting in a range of model complexities with trade-offs between computational demand, accuracy, and scalability.
All RTMs require inputs in the form of external conditions (e.g., incident solar
Glossary